John R. Mayer received his bachelor of arts degree from the University of California, Santa Barbara in 1994 and graduated cum laude from Thomas Jefferson School of Law in 1998, where he was a member of the Thomas Jefferson Law Review. After passing the bar, he practiced with the mid-sized law firm Hayes Simpson Greene LLP until late 2001, at which time he began his own practice. Since then, he has practiced with a partner and as a solo practitioner, and established John R. Mayer, APLC in 2005.

Mr. Mayer has represented plaintiffs and defendants in a vast array of lawsuits, including business disputes, real estate matters, personal injury cases, investor claims, and probate cases. Mr. Mayer has also represented businesses and individuals in transactions, collection matters, pre-lawsuit negotiations, and appeals.

Mr. Mayer is a member of the board of directors for San Diego Teen Court, Inc., a non-profit peer sentencing program for first-time juvenile offenders. He is also a member of the San Diego County Bar Association.